As one line of household furniture there are known dining tables and salon tables having decorative patterns such as plants, scenery etc. on the surface. They are ready made in a manufacturing plant by fixing a top surface panel material having a decorative pattern, i.e. a top plate, with leg parts by woodwork or by using metal fixing devices. The reason for that is because if a base plate and a top plate having a decorative pattern were separately fabricated in a plant and assembled at a retailer's shop, this operation would be troublesome and it would be impossible to fix the base plate and the top plate with their four corners in the exact positions. For that reason, the so-called knock-down production of furniture involving top plates has thus been impeded. Also in ordinary homes, coffee shops etc. where such furniture is used, it is difficult to separate both plates. Therefore, for example, when it was desired to change the interior decoration by replacing the top plate by another one having a different pattern or by one having no decoration, according to changes of the seasons, it has been necessary to change the whole piece of furniture, i.e. the dining table, the salon table or the like, into a new one, and therefore very uneconomical. Furthermore, in the case where a scratch or scratches on the top plate of the table become outstanding sufficiently to be rejected for commercial use, it was also necessary to change the whole table into a newly bought one.
This invention provides fixing devices which can be obtained by the knock-down production, which can easily and removably fix a top plate and a base plate (the side where legs are provided) by preparing one base plate and several top plates having different patterns and changing the top plates when the interior decoration is desired to be changed, for example, in each season, and which are in such structure that a molded part, i.e. a male form, to be fixed with a top plate is inserted into another molded part, i.e. female form, to be fixed with a base plate and both plates are tightly fixed and secured by an engaging rod.